This invention relates to frames for vents in building walls. 2. Prior Art
Customarily vents in concrete walls have been framed in connection with the concrete wall forms so that, when the concrete has been poured and the formwork removed, the vent aperture remains in the concrete. Sometimes cloth screen has been included in the formwork, so that the margin of the screen will be embedded in concrete to hold it in position covering the vent. In other instances screen cloth has been secured over one of the aperture sides after the formwork has been removed.
In wood walls vent apertures have simply been cut or formed in the walls and then covered with screen cloth.